How to know he likes me?

I've been seeing this guy for a bit more than a month now, but we're not like going out, but somehow we give off the feeling that we are.. he calls me everyday and we always talk for like an hour or more.. somehow i feel like he likes me, but he still hasn't made any move yet.. how can i talk to him about it? Should i be blunt and start talking directly about it or how can i bring it up subtly? I dont have that much experience :/ hope you guys can help!